E-Day: The moment the machines evolved and humans nearly went extinct. In the chaos, one million people escaped Earth and fled to a secret colony on the dark side of the Moon. Deep beneath the lunar surface, in the cold, they wait for the inevitable--a second attack that will wipe humanity out forever.

Sergeant Tadhg Walsh is tired of waiting. He wants to fight back and return to Earth to search for Shadow Squad. But he has new orders from the Lunar Defense Corps: protect the colonies at all costs and forget about any survivors back home.

Captain Akira Hayashi is one of those survivors, forced to heal from his injuries in a submarine while the planet burns. Shadow Squad won't be hiding for long, but before they can don their armor again, they must find a safe haven to plan their attack. When they locate a research station in the Mariana Trench, their submarine heads into the depths. What they find in the darkness changes everything they know about E-Day.

On the Moon, the LDC will do everything in its power to keep the truth about survivors on Earth a secret, even if it means sacrificing the few for the many. On Earth, Shadow Squad will have to make tenuous alliances with old enemies to stand a chance against the enemy. If they can unite, they might just have a chance of stopping the machines from wiping out humanity on Earth and the Moon.